Nadal continues to reign on clay

One Spanish king may have abdicated but Rafael Nadal looks determined to hang onto his crown as the king of clay.

The world number one maintained his record of not having dropped a set at this year's French Open with a 6-1 6-2 6-1 victory over Serbian Dusan Lajovic in the fourth round.

Lajovic, 23, was playing in only his second grand slam tournament and it was certainly a baptism of fire for his first match on Court Philippe Chatrier.

Nadal, on the day when King Juan Carlos of Spain announced he was abdicating after 39 years on the throne, won the first five games before Lajovic finally got on the board.

His start to the second set was even worse, Nadal winning the first 17 points, although Lajovic then managed to hold two successive service games.

He had three chances to break the Nadal serve and make it 5-3 but the eight-time champion fought back.

Lajovic managed a final hurrah by breaking the Spaniard's serve at 0-5 in the third set but Nadal, who has lost just 23 games in four matches, promptly broke again to love to clinch victory in a sprightly hour and 33 minutes.

Nadal revealed after his previous match against Leonardo Mayer that he was again feeling the back problem that so badly affected him in the Australian Open final against Stan Wawrinka.

It clearly has not hampered his progress so far but the draw has been kind and he will face his first real test in the quarter-finals against compatriot David Ferrer.

The fifth seed, who Nadal beat in the final 12 months ago, lost his first set of the tournament against Kevin Anderson on Sunday but was nevertheless an impressive 6-3 6-3 6-7 (5/7) 6-1 winner.

Ferrer was well beaten last year but this match, his 10th consecutive grand slam quarter-final, will have an extra edge because of the outcome of their last meeting.

In Monte Carlo in April, Ferrer beat Nadal on clay for the first time in 10 years, one of three defeats the world number one has suffered in the build-up to Roland Garros.